Pixel circuit and display device including the same

Abstract

A pixel circuit may include a light-emitting element, a driving transistor which applies a driving current to the light-emitting element, a storage capacitor connected to a control electrode of the driving transistor, a data voltage-applying transistor which applies a data voltage to the storage capacitor, an emission transistor which connects the driving transistor to the light-emitting element in response to an emission signal, and a bias capacitor disposed between a first electrode of the driving transistor and a control electrode of the emission transistor.

What is claimed is: 
     
       1. A pixel circuit comprising:
 a light-emitting element; 
 a driving transistor which applies a driving current to the light-emitting element and includes a control electrode and a first electrode; 
 a storage capacitor connected to the control electrode of the driving transistor; 
 a data voltage-applying transistor which is directly connected to the storage capacitor and directly applies a data voltage to the storage capacitor; 
 an emission transistor which connects the driving transistor to the light-emitting element in response to an emission signal and includes a control electrode; and 
 a bias capacitor disposed between the first electrode of the driving transistor and the control electrode of the emission transistor. 
 
     
     
       2. The pixel circuit of  claim 1 , wherein the emission transistor is a P-type transistor. 
     
     
       3. The pixel circuit of  claim 1 , wherein the light-emitting element includes an anode electrode, and
 wherein the pixel circuit further comprises a light-emitting element initialization transistor which applies a first initialization voltage to the anode electrode of the light-emitting element. 
 
     
     
       4. The pixel circuit of  claim 3 , wherein the light-emitting element initialization transistor applies the first initialization voltage to the anode electrode of the light-emitting element in response to the emission signal,
 wherein the light-emitting element initialization transistor is an N-type transistor, and 
 wherein the emission transistor is a P-type transistor. 
 
     
     
       5. The pixel circuit of  claim 1 , further comprising a data initialization transistor which applies a second initialization voltage to the control electrode of the driving transistor. 
     
     
       6. The pixel circuit of  claim 1 , further comprising a threshold voltage compensation transistor disposed between the control electrode of the driving transistor and the first electrode of the driving transistor. 
     
     
       7. The pixel circuit of  claim 1 , further comprising a reference voltage-applying transistor which applies a reference voltage to the storage capacitor. 
     
     
       8. The pixel circuit of  claim 7 , wherein the driving transistor further includes a second electrode which receives a driving power voltage, and wherein the reference voltage is identical to the driving power voltage. 
     
     
       9. The pixel circuit of  claim 7 , further comprising a threshold voltage compensation transistor disposed between the control electrode of the driving transistor and the first electrode of the driving transistor, and
 wherein a control signal applied to a control electrode of the reference voltage-applying transistor is identical to a control signal applied to a control electrode of the threshold voltage compensation transistor. 
 
     
     
       10. A pixel circuit comprising:
 a light-emitting element; 
 a driving transistor which applies a driving current to the light-emitting element and includes a control electrode and a first electrode; 
 a storage capacitor connected to the control electrode of the driving transistor; 
 a data voltage-applying transistor which is directly connected to the storage capacitor and directly applies a data voltage to the storage capacitor; 
 an emission transistor which connects the driving transistor to the light-emitting element in response to an emission signal; and 
 a bias capacitor including a first electrode which receives a bias signal and a second electrode connected to the first electrode of the driving transistor. 
 
     
     
       11. The pixel circuit of  claim 10 , wherein the emission transistor is a P-type transistor. 
     
     
       12. The pixel circuit of  claim 11 , wherein the bias signal rises from a low voltage level to a high voltage level while the emission signal has the high voltage level. 
     
     
       13. The pixel circuit of  claim 10 , further comprising a light-emitting element initialization transistor which applies a first initialization voltage to an anode electrode of the light-emitting element. 
     
     
       14. The pixel circuit of  claim 13 , wherein the light-emitting element initialization transistor applies the first initialization voltage to the anode electrode of the light-emitting element in response to the bias signal,
 wherein the light-emitting element initialization transistor is an N-type transistor, and 
 wherein the emission transistor is a P-type transistor. 
 
     
     
       15. The pixel circuit of  claim 10 , further comprising a data initialization transistor which applies a second initialization voltage to the control electrode of the driving transistor. 
     
     
       16. The pixel circuit of  claim 10 , further comprising a threshold voltage compensation transistor disposed between the control electrode of the driving transistor and the first electrode of the driving transistor. 
     
     
       17. The pixel circuit of  claim 10 , further comprising a reference voltage-applying transistor which applies a reference voltage to the storage capacitor. 
     
     
       18. The pixel circuit of  claim 17 , wherein the driving transistor further includes a second electrode which receives a driving power voltage, and wherein the reference voltage is identical to the driving power voltage. 
     
     
       19. The pixel circuit of  claim 17 , wherein the reference voltage-applying transistor comprises a control electrode,
 wherein the pixel circuit further comprises a threshold voltage compensation transistor disposed between the control electrode of the driving transistor and the first electrode of the driving transistor, and 
 wherein a control signal applied to the control electrode of the reference voltage-applying transistor is identical to a control signal applied to a control electrode of the threshold voltage compensation transistor. 
 
     
     
       20. A display device comprising:
 a display panel including pixels, each of the pixels comprising:
 a light-emitting element; 
 a driving transistor which applies a driving current to the light-emitting element and includes a control electrode and a first electrode; 
 a storage capacitor connected to the control electrode of the driving transistor; 
 a data voltage-applying transistor which directly connected to the storage capacitor and directly applies a data voltage to the storage capacitor; 
 an emission transistor which connects the driving transistor to the light-emitting element in response to an emission signal; and 
 a bias capacitor connected to the first electrode of the driving transistor; 
 
 a gate driver which provides a gate signal to the pixels; 
 a data driver which provides the data voltage to the pixels; 
 an emission driver which provides the emission signal to the pixels; and 
 a driving controller which controls the gate driver, the data driver, and the emission driver. 
 
     
     
       21. The display device of  claim 20 , wherein the bias capacitor includes a first electrode connected to a control electrode of the emission transistor and a second electrode connected to the first electrode of the driving transistor. 
     
     
       22. The display device of  claim 20 , wherein the bias capacitor includes a first electrode which receives a bias signal and a second electrode connected to the first electrode of the driving transistor.